INFLUENCE DE TRAITEMENTS PRÉALABLES AU FROID SUR LA CROISSANCE ET LE DÉVELOPPEMENT DU POINSETTIA

1990 ◽  
Vol 70 (1) ◽  
pp. 363-368
Author(s):  
SERGE GAGNON ◽  
BLANCHE DANSEREAU
Keyword(s):  
Dry Weight ◽  
Flower Head ◽  
Euphorbia Pulcherrima ◽  
Rapid Adaptation ◽  
Night Temperature ◽  
Flower Buds ◽  
Cold Night ◽  
Head Diameter ◽  
Significant Difference ◽  
Temperature Pretreatment

To achieve more rapid adaptation of plants grown under a constant cold night temperature regime, rooted poinsettia (Euphorbia pulcherrima Willd ex. Klotzsch ’Annette Hegg Dark Red’) cuttings were given one of several cold pretreatments (TPF): either 17/13 °C or 13 °C for 5, 10, or 15 d. The influence of these TPF treatments was compared with that of control plants where the night temperature was 17 °C. There was no significant difference for the number of days to the first visible flower buds and to anthesis, for the number of flowering stems and bracts formed, for leaf area and aerial dry weight. However, the TPF treatment of 17/13 °C given for 15 d caused a significant increase in bract area, and of average flower head diameter compared to those plants given a TPF treatment of 13 °C for the same length of time.Key words: Euphorbia pulcherrima, night temperature, split night temperature, pretreatment

INFLUENCE D’UN PRE-TRAITEMENT AU FROID ET DE LA TEMPERATURE NOCTURNE SUR LA CROISSANCE, LE DEVELOPPEMENT ET LE CONTENU EN ELEMENTS MINERAUX DE PLANTS DE POINSETTIA

1985 ◽  
Vol 65 (4) ◽  
pp. 1001-1010
Author(s):  
MICHEL SENECAL ◽  
BLANCHE DANSEREAU
Keyword(s):  
Temperature Regime ◽  
Dry Weight ◽  
Euphorbia Pulcherrima ◽  
Rapid Adaptation ◽  
Night Temperature ◽  
Flower Buds ◽  
Cold Pretreatment ◽  
Top Dry Weight ◽  
Pre Treatment ◽  
Nitrogen Phosphorus

To achieve more rapid adaptation of plants grown under a constant or split night temperature regime, two poinsettia cultivars (Euphorbia pulcherrima Willd ex. Klotzsch), Annette Hegg Dark Red (AHDR) and Annette Hegg Top White (AHTW), were given a cold pretreatment (PF). The PF was a 13 °C air temperature regime provided for 15 h a night during a 10-day period. The number of days to the first visible flower buds and to anthesis was longer for both cultivars having received a PF than the control plants (no pre-treatment). For AHDR only, plant height, top dry weight, the number and bract area were significantly lower after the PF when considering the average of the night temperature treatments. Regardless of the cultivar tested, no significant differences in bract diameter and root dry weight were observed between the control plants and those given a PF treatment. Whether the two cultivars were given a PF treatment or not, the split night temperature (TNP) of 16.3/14.2 °C caused a nonsignificant delay, from the appearance of first visible flower buds to anthesis, compared to those held at 16.7 °C. The most important delay of these parameters as well as the greatest reduction of bract area was obtained under a 10.8 °C night temperature. The TNP of 16.6/10.8 °C produced plants (PF or control), of both cultivars with a greater bract number and top dry weight. For the two cultivars given a PF treatment, the levels of nitrogen, phosphorus, calcium, and magnesium were greater when considering the means of the night temperature treatments.Key words: Euphorbia pulcherrima, cold pretreatment, night temperature, split night temperature

scholarly journals Growth of Cyclamen as Affected by Day and Night Temperatures

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 466G-467
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Dry Weight ◽  
Flowering Plants ◽  
Flower Size ◽  
Night Temperature ◽  
Flower Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Average Daily Temperature ◽  
Positive Difference ◽  
Significant Difference

The growth of Cyclamen persicum Mill. `Laser Scarlet' and `Sierra Scarlet' was evaluated for plants grown at day/night temperature differences of +9, +3, 0, –3 or –9°C. The day temperature was maintained for the duration of the 16-hr photoperiod and the day and night temperatures were selected to provide an average daily temperature of 16°C. The plants were grown at the specific temperatures starting 15 weeks from seeding until flowering. Total daily irradiance was 10 mol/day per m2. There was no significant difference in time to flower for plants of `Laser' (115 10.3 days from transplant). Flower buds appeared earlier above the foliage for `Sierra' plants grown at negative differences of 3 or 9°C (113 11.4 days) compared to plants grown at constant 16C (124 9.7 days). At flowering, plants grown with a positive difference of 9°C were significantly taller (22 1.9 cm for `Laser' and 24 2.0 cm for `Sierra') than the plants at 16C (19 1.9 cm for `Laser' and 21 2.1 cm for `Sierra'). Plants of `Laser' grown at +3C difference were also taller (21 2.1 cm) than the control plants at 16°C. Plant dry weight was larger for plants of both `Laser' and `Sierra' grown with +9°C. There were no differences in flower number or flower size among plants within each cultivar grown at the different temperature conditions.

scholarly journals Temperature and Duration of Pretreatment Effects on Growth and Development of Geraniums

HortScience ◽  
1992 ◽  
Vol 27 (3) ◽  
pp. 216-217
Author(s):  
Serge Gagnon ◽  
Blanche Dansereau
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Dry Weight ◽  
Rapid Adaptation ◽  
Night Temperature ◽  
Flower Buds ◽  
Shoot Dry Weight ◽  
Temperature Regimes ◽  
Pretreatment Effects

Geranium seedlings (Pelargonium ×hortorum Bailey `Smash Hit Red') were given various cold pretreatments (CP) to obtain more rapid adaptation to constant or split-night temperature regimes. The six following CP were used: either 13C or 17/13C for 5, 10, or 15 days. The effect of these CP given at seedling stage was compared with that of control plants held at 17C at night. The CP did not significantly increase the time to first visible flower buds or to anthesis. The number of flowering stems, plant height, shoot dry weight, and leaf area of control plants were not significantly different from plants receiving CP.

FERTILIZATION AND NIGHT TEMPERATURE EFFECTS ON GROWTH AND CARBOHYDRATE STATUS OF POINSETTIA

1989 ◽  
Vol 69 (1) ◽  
pp. 347-349
Author(s):  
M. SENÉCAL ◽  
B. DANSEREAU ◽  
R. PAQUIN
Keyword(s):  
Temperature Effects ◽  
Sugar Content ◽  
Dry Weight ◽  
Total Sugar ◽  
Euphorbia Pulcherrima ◽  
Night Temperature ◽  
Total Sugar Content ◽  
Carbohydrate Levels ◽  
Carbohydrate Status ◽  
Fertilizer Rates

Poinsettia (Euphorbia pulcherrima Willd ’Annette Hegg Dark Red’) were fertilized with 3.0, 4.5 or 6.0 g per 15-cm pot of Osmocote (14N-6.1P-11.6K) and were grown in greenhouses at 9, 13, or 17 °C night temperature. As the night temperature increased, the number of days to anthesis, bract number and carbohydrate levels decreased. Maximum bract mean area and minimum root dry weight were achieved at 13 °C. High fertilizer rates increased the number of days to anthesis while bract number, root and shoot dry weights, reducing and total sugar content decreased.Key words: Euphorbia pulcherrima, fertilization, night temperature, carbohydrate

scholarly journals 543 Flowering and Growth Response to Photoperiod and Cold Treatment of Arabis sturii Mottet

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 539D-539
Author(s):  
Donglin Zhang ◽  
A.M. Armitage ◽  
J.M. Affolter ◽  
M.A. Dirr
Keyword(s):  
Flower Development ◽  
Growth Response ◽  
Cold Treatment ◽  
Dry Weight ◽  
Flower Initiation ◽  
Flower Buds ◽  
Significant Difference ◽  
New Crop ◽  
Treatment Number ◽  
Pot Plant

Arabis sturii Mottet (Brassicaceae) has potential as a new crop for American nurseries and may be used as a perennial pot plant. Cold treatment was required for flowering of Arabis sturii and a 6-week cold treatment resulted in the greatest number of racemes and flowers per plant. Increasing or decreasing length of cold treatment resulted in less flowers per plant. Plant height increased as duration of cold treatment increased. Photoperiod had a significant effect on flowering and growth only after plants received 3 weeks or more cold treatment. All plants given a 16-h photoperiod flowered, while only 50% and 80% flowered under an 8- or 12-h photoperiod, respectively. A 16-h photoperiod shortened the time to production of flower buds and anthesis and the greatest difference occurred after the 9-week cold treatment. At the 6-week cold treatment, number of flowers per plant different significantly between long (145 flowers) and short day (59). The effect of photoperiod on number of flowers per plant became less as cold treatment increased or decreased. Although photoperiod did not induce flower initiation, it had a tremendous effect on flower development. Many more flowers were produced and plants were taller as photoperiod increased. No significant difference was found in plant dry weight.

Effect of planting date and density on calendula and peppermint herbs

2014 ◽  
Vol 1 (1) ◽  
pp. 25-29
Author(s):  
Rahim Mohammadian ◽  
Behnam Tahmasebpour ◽  
Peyvand Samimifar
Keyword(s):  
Mutual Effect ◽  
Dry Weight ◽  
Planting Date ◽  
Mass Reduction ◽  
Flower Number ◽  
Planting Dates ◽  
Randomized Design ◽  
Significant Difference ◽  
Completely Randomized Design ◽  
Total Maximum

A factorial experiment was conducted with a completely randomized design to evaluate the effects of planting date and density on calendula herbs and peppermint. It had 3 replicates and was done in Khosroshahr research farm, Tabriz in 2006. Under studied factors were: 3 planting dates (10 May, 25 May and 10 June) in 4 densities (25, 35, 45, 55) of the plant in square meters. The results of variance a nalysis showed that there was 1% probability significant difference between the effects of planting date and bush density on the leave number, bush height and the bush dry weight. But the mutual effect of the plant date in mentioned traits density was insignificant. Regarding the traits mean comparison, the total maximum dry weight was about the 55 bush density in mm. Also, the bush high density in mm causes the bush growth and its mass reduction. When there is the density grain, the flower number will increase due to bush grain in surface unit. Overall, we can conclude that 10 June planting and 45 bush density in mm is the most suitable items and results in favored production with high essence for these crops.

Evaluation of Nurse Crops for Weed Control and Plant Establishment in Prairie Restoration

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 485b-485
Author(s):  
Lisa M. Barry ◽  
Michael N. Dana
Keyword(s):  
Plant Biomass ◽  
Spring Barley ◽  
Dry Weight ◽  
Site Quality ◽  
Prairie Restoration ◽  
Plant Establishment ◽  
Significant Difference ◽  
Nurse Crops ◽  
Partridge Pea ◽  
Prairie Plant

Nurse crops are often recommended in prairie restoration planting. This work investigated several alternative nurse crops to determine their utility in prairie planting. Nurse crops were composed of increasing densities (900, 1800, or 2700 seeds/m2) of partridge pea, spring oats, spring barley, Canada wild rye, or equal mixtures of partridge pea and one of the grasses. The experimental design was a randomized complete-block set in two sites with three blocks per site and 48 treatments per block. Each 3 × 3-m plot contained 1 m2 planted in Dec. 1995 or Mar. 1996 with an equal mix of seven prairie species. The nurse crops were sown over each nine square meter area in April 1996. Plots lacking nurse crops served as controls. Evaluated data consisted of weed pressure rankings and weed and prairie plant dry weight. Nurse crop treatments had a significant effect on weed pressure in both sites. Barley (1800 and 2700 seeds/m2) as well as partridge pea + barley (2700 seeds/m2) were most effective at reducing weed pressure. When weed and prairie plant biomass values were compared, a significant difference was observed for site quality and planting season. Prairie plant establishment was significantly greater in the poorly drained, less-fertile site and spring-sown plots in both sites had significantly higher prairie biomass values. Overall, after two seasons, there was no advantage in using nurse crops over the control. Among nurse crop treatments, oats were most effective in reducing weed competition and enhancing prairie plant growth.

Cyclamen Leaf Unfolding Rate in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Day Length ◽  
Leaf Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Unfolding ◽  
Significant Difference ◽  
Number Of Leaves ◽  
Growth Chambers ◽  
Response To Temperature

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).

INFLUENCE OF CLIPPING HEIGHT ON THE NEUTRAL CARBOHYDRATE LEVELS OF ROOT EXUDATES OF ALFALFA PLANTS GROWN UNDER GNOTOBIOTIC CONDITIONS

1972 ◽  
Vol 52 (4) ◽  
pp. 643-649 ◽  
Author(s):  
R. A. HAMLEN ◽  
F. L. LUKEZIC ◽  
J. R. BLOOM
Keyword(s):  
Root Exudates ◽  
Dry Weight ◽  
Root Tissue ◽  
Minor Components ◽  
Flower Buds ◽  
Total Sugars ◽  
Spectral Techniques ◽  
Mass Spectral ◽  
Mature Leaves ◽  
Carbohydrate Levels

Influence of clipping height on neutral carbohydrate levels in root exudates of alfalfa grown gnotobiotically was investigated by gas-chromatographic and mass-spectral techniques. Exudates were obtained from plants that were lightly clipped (removal of flower buds), intermediately clipped (15 cm), and severely clipped (removal of all but four mature leaves). Glucose, inositol, sucrose, and four unidentified (U) components were detected. Fluctuations in the level of sugars were observed in exudates from two sampling periods. Glucose and U1 were most concentrated under light clipping. Levels of inositol and sucrose were maximum under intermediate clipping. Amounts of U3 were greatest from severely clipped plants, whereas levels of U5 remained constant at all cuttings. Concentration of U4 was lowest under severe clipping. U2, present in exudates from seedling plants, was not detected. Quantities of sugars released per gram of dry weight of root tissue were greater under severe clipping. U1 was the major component, with glucose, inositol, and sucrose minor components of the total sugars.

Acetyl salicylic acid alleviates chilling-induced damage in muskmelon seedlings

2007 ◽  
Vol 87 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Ahmet Korkmaz ◽  
Murat Uzunlu ◽  
Ali Riza Demirkiran
Keyword(s):  
Salicylic Acid ◽  
Cucumis Melo ◽  
Chilling Stress ◽  
Foliar Spray ◽  
Dry Weight ◽  
Acetyl Salicylic Acid ◽  
Signal Molecule ◽  
Stress Indicator ◽  
Shoot Dry Weight ◽  
Significant Difference

Salicylic acid (SA) is a common plant-produced signal molecule that is responsible for inducing tolerance to a number of biotic and abiotic stresses. An experiment was, therefore, conducted to test whether acetyl salicylic acid (ASA) application at various concentrations through seed immersion or foliar spray would protect muskmelon [Cucumis melo L. (Reticulatus Group)] seedlings subjected to chilling stress. Twenty-one-day-old plants pre-treated with ASA (0, 0.1, 0.25, 0.50 or 1.0 mM) were subjected to chilling stress for 72 h at 3 ± 0.5°C. ASA, applied either through seed immersion or foliar spray, was effective within the range of 0.1 to 1 mM in inducing tolerance to chilling stress in muskmelon seedlings; however, there was no significant difference between application methods. ASA significantly and curvilinearly affected all seedling growth and stress indicator variables tested except shoot dry weight. The best protection was obtained from seedlings pre-treated with 0.5 mM ASA. The highest ASA concentration used was slightly less effective in providing chilling stress protection. Even though both methods provided similar means of protection, due to its simplicity and practicality, immersion of muskmelon seeds prior to sowing in 0.5 mM ASA would be a more desirable method to induce tolerance to chilling stress. Key words: Cucumis melo, aspirin, chilling stress tolerance, gas exchange, electrolyte leakage

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